Sound-recording apparatus.



PATENTED JUNE '23, 1908.

v 0. L. GHISHOLM; SOUND RECORDING APPARATUS.

APPLICATION FILED JULY 15, 1907.

2 SHEETS-SHEET 1.

ATTORNEYS PATEN TED JUNE 23, 1908.'

0. LVOHISHOLM. .SOIIND RECORDING APPARATUS.

APPLICATION FILED JULY 15, 1907.

2 SHEBTSSHBET 2.

LZarlasL Lfizls/zahz [WNW A TTORNE Y5 is a specification.

CHARLES LOGAN GHISHOLM, OF EDMONTON, ALTA, CANADA.

SOUND-RECORDING- APPARATUS.

- To all whom it may concern:

- Be it known that 1, CHARLES LOGAN GinsnoLM, a subject of the King of England, residing at Edmonton, Alta, Dominion of Canv5 ada, have invented anew and useful Sound- Recording Apparatus, of which the following This invention relates to apparatus of that class employed in recording the vibrations of a telephone receiver, and has for its principal object to provide a novel mechanism which may be applied to existing phonographs, graphophones, and similar sound recording machines at small cost. v

4 A further object of the invention is to improve and simplify the construction and arrangement of the diaphragm, the recording stylus, and the electro magnet of the receiver.

. With these and other objects in view, as will more fully hereinafter appear, the invention consists in certain novel features of construction and arrangement of parts, hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of the struc ture may be made without departing from the spirit or sacrificing any ofthe advantages the invention.

In the accompanying drawings-:Figure 1 is a perspective view, partly in the nature ofa diagram, illustrating a sound recording machine arranged to be operated froma distant transmitter. Fig. '2 is a cross sectional viewof the recording mechanism. Fig. 3 is a view similar to Fig. 2, illustrating a modification of the invention. Fig. 4 is a detail Fig. 3 detached. Fig. 5 is an elevation looking from the rear of the dia hragm carrier.

"Similar numerals of re erence are r employed to indicate corresponding arts throughout the several figures of the rawln the drawings there is shown a portion of a phonograph, graphophone, or similar instrument, Abeing the record, B the screw shaft, C the nut carrying arm and D the pivoted sound box carrier, the carriage being supported by a rod E that is parallel with the screw shaft ,B.

The carriage is provided with an obliquely disposed arm 10 to which is secured a cylinder 1] that may be formed of any suitable Specificationof Letters Patent. Application filed July 15, 1907. Serial'No. 383,761.

perspective view of the counter-weight of' Patented June 23, 1908.

material, preferably aluminum, in order that the weight may be as small as possible. To the lower edge of the cylinder 11 is secured a diaphragm 12, the eriphery of the diaphragm being secured to the cylinder in any suitable manner, and the diaphragm being formed of iron as is usual in telephonic receivers, or it may be formed of other suitable material and provided with a small iron armature' The diaphragm is arranged to actuatea recording stylus 15, the stylus being secured to an arm 16 which may be fastened to the diaphragm. The stylus arm is provided with a projecting tongue 18 which engages with the central portion of the diaphragm and is held in contact therewith by a spring arm 19 -which may be adjusted for the purpose of varying the degree of force exercised in keeping the stylus tongue and diaphragm in con tact. Other forms of stylus, however, may

wires 22 to bindingposts 23 at the outer closed The pole iece of' the end of the cylinder. magnet is arranged adjacent to t e center of vbe employed and the stylus may, if necessary,

the diaphragm, and the operation of the diaphragm is similar to that of an ordinary receiver.

In order to adjust the position of the mag-- net with relation to the diaphragm, screws 25 are employed at the side walls of the casing, these screws extending through into contact with the side bars of the magnet, while at the rear wall of the casing is an adjusting screw 26 having a knurled knob or handle 27 which may be turned for the effecting close adjustment of the e ectro-magnet with, relation to the diaphragm, after ,which the electro-magnet may be locked in place by'the screws 25 and a locking nut 28 on the screw 26.

It will be noted-0n reference to Fig. 2 that the center of avity of the electro-magnetic urpose of sound box is ut slightly to one side of the vertical plane of the axis of the supportin shaft 20, owing to the oblique position of the sound box. The weight, however, would be too great for ordinary pur oses if imposed on the stylus, and in order t at the pressure on the stylus may be reduced to correspond to that of an ordinary recorder, the sound box carriage 18 provided with a cou nter-weight 30, th s weightwbeing slightly less than that of the Weight of the electro-magnetic sound box,

so that the latter will be free torise and fall as the recording operation progresses.

In order to avoid the necessity of moving the whole of the electro-magnetic sound box, the diaphragm may be separately supported,

as shown in Fig. 3. In this construction a -move.

-. The diaphragm supporting disk 40 is provided with a central opening 45 in alinement with the polepiece of, the electromagnet, and bearing against this disk are a number of Weights 46 that are connected together by a sleeve 47 encircling the pole piece, but out of contact therewith. The weights are further guided by a pair of anti-friction balls 49 that bear against the parallel sides of the magnet above the spool and are connected by a ring 50. The two rings 47 and 50 are connected together by a pair of bars 51, and the whole forms a weight of such nature as to maintain the stylus in operative position without subjectin it to such pressure as might interfere wit the recording operation. In this latter construction the diaphragm assumes a distance from the end of the pole piece corresponding to the diameter of the recording cylinder, but this variation is not in itself sufiicient to interfere with the proper operation of the device, especially where new recording cylinders are employed. After the cylinders have been shaved a number of times, however, the distance between the d1aplhragm and the pole piece may interfere wit the proper o eration of the diaphragm and in such cases t e cylinder is lowered. In order to accomplish this the'cylinder su porting arm of the carriage is referabl y made in two sections, as shown in ig. 3, and these are connected by an adjusting screw 61, so that the position of the cylinder may be accurately adjusted.

In connecting. up' the instrument, it is merely necessary to use an ordinary telephone circuit and in Fig. 1 there'has been shown a transmitter X in front of which is .a trumpet Y, which may be used where sound waves from a iano or other instrument are to be recorde or in case a record is to be made of acon'cert;

The ap aratus may be emplo ed for mak-' d of music played at distant points,

ceiver for thepur ose of recording a message over a telephone ine, any suitable switching connections being employed, if necessary or desired, for the purposeof starting the recording device into 0 eration automatically when' a called subscr1 er is absent from his oflice or business. The records made will be exact reproductions of the vibrations of the diaphragm and these may be reproduced by any ordinary reproducer in commercial use.

I claim i 1. The combination with a revoluble record carrier, of a carriage movable in a direction parallel with the axis of the carrier, a casing supported by said carriage, a diahragm secured to and forming a vibratory bottom member for the casing, a stylus connected to and movable with said diaphragm, an electro-magnet mountedwithin the casing, and means for counter-balancing a portion of the weight of the casing audits contents to thereby revent undue pressure of the stylus against t e record.

. 2. In sound recording apparatus, a stylus, adiaphragm for operating t e same, an electro-magnet for actuating the diaphra m, a casing mclosing the electro-magnet an supportin the diaphragm, an ad ust1ng screw carrie by the casingand serving to move the electro-magnet toward and from the diaphragm, and lockin screws for holding the electro-magnet in a justed position.

3.- Insound recording apparatus, a casing, an electro-Inagnet therefor, a stylus, a dia phragm for actuating the same, a diaphragm carrying disk having an openmg ad acent the pole piece of the magnet, a plurality of Weights bearing against said disk, a ring connecting said weights, a second ring encircling a art of the electro-ma net, anti-frict on balls carried by the secon rin and bear ng against the electro-magnet, an a connecting bar between the two rings.

In testimony that I claim the foregoing as -my own, I have hereto afiixed my signature in the presence of two witnesses.

CHARLES LOGAN CHISHOLM. Witnesses:

' T. AMOS WILSON,

RICHARD B. HANSON. 

